Poll numbers tell the story. A Gallup survey taken within a week of his announcement in August put the Texas governor at 29% among Republican and Republican-leaning independents. Mitt Romney was in second place with 17%.

By the time the contests came around this month, Perry's campaign had fizzled. He placed fifth in Iowa and last in New Hampshire, where he didn't compete.

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And while Perry vowed to "win" in South Carolina, the final poll that included him, from CNN/Time/ORC International this week, put him at 6% among likely voters in the state's primary.

In announcing Thursday that he was suspending his campaign -- a move that allows candidates to continue raising and spending campaign funds -- Perry said he saw "no viable path forward."

Political analysts have long pointed to Perry's own gaffes to explain how he lost so much appeal.

The most memorable took place in debates, and can be summarized with a single word: oops.

In November, Perry spent a painfully awkward 53 seconds trying to remember the third federal agency that he would want to cut if he were president. Ultimately, he said he couldn't remember. "Sorry," he said. "Oops."

"It is all about the debates. The debates were the first primaries," said Gloria Borger, CNN's chief political analyst. "And once Rick Perry said 'oops,' it was very difficult for him to regain his footing."

"This was a campaign in which the candidate looked great in theory but not in practice," she added.

Another incident added to the damage. Speaking to a group of college students in New Hampshire, he flubbed both the country's voting age and the date of the presidential election, telling the students he would appreciate their votes if they were 21 by November 12. The U.S. voting age is 18, and the election is November 6.

Perry may also have lost some support in how he handled his disappointing finish in Iowa.

He had fought for votes in the state and worked to appeal to conservative caucus-goers. He hardened his stance on abortion, saying he had decided to oppose abortions in all cases, including rape and incest.

Speaking to reporters after his fifth-place finish in the state, Perry said said he would "return to Texas, assess the results of tonight's caucus, determine whether there is a path forward for myself in this race."

He soon announced he was staying in the race and would head to South Carolina.

"He defied the principles of politics: Never let them see you sweat, never let them think that you're thinking about leaving," said Candy Crowley, CNN's chief political correspondent.

In the end, Perry's departure from the race came as little surprise.

"Rick Perry tried to put everything on South Carolina" but realized he "clearly would get embarrassed," said CNN political analyst Roland Martin.

CNN contributor Will Cain agreed. "Why would Rick Perry get out right now? Because Rick Perry is a political animal. He has been a career politician.

"Whether or not he stays in politics or he wants to influence politics in the future, getting out now helps that. Getting last place in South Carolina hurts you."

"This has been a painful fall for Rick Perry," Crowley said. "And, obviously, one he didn't want to continue."